Cluster mill, in particular, a six-high cluster mill, comprising an axial displacement and holding device for displaceably mounted intermediates rolls and or working rolls

ABSTRACT

A cluster mill includes an axially displacing and holding device for displaceable intermediate and/or working mills ( 11 ), with the chocks ( 7 ) being guided in a sliding manner inside the cluster mill stand housing posts ( 1 ), the rolls ( 11 ) are be displaced in axially opposite directions by piston-cylinder units ( 5 ), and the piston rods ( 5   a ) are pivotally connected to a main traverse ( 4 ). In order to prevent the main traverse ( 4 ) from becoming damaged by non-uniform action of the piston-cylinder units ( 5 ) during displacement, there are provided moving beams ( 1   a ), which are located on both sides of the chock ( 7 ) and are mounted inside the cluster mill stand housing posts ( 1 ) via the connecting traverses ( 2 ), the connecting traverses ( 2 ) being pivotally connected to the middle of the main traverse ( 4 ), whereby the piston rods ( 5   a ) of the piston-cylinder units ( 5 ) are pivotally connected to opposite ends ( 4   a,    4   b ) of the main traverse ( 4 ), and each piston-cylinder unit ( 5 ) is controlled according to path by a displacement sensor ( 10 ).

The invention relates to a cluster mill, in particular a six-highcluster mill with an axially displacing and holding device fordisplaceably supported intermediate rolls and/or working rolls, whereinchocks are slidably displaced in rolling mill stands in a direction of aroll separating force, and wherein the intermediate rolls and/or workingrolls, together with their respective chocks, are displaceable inaxially opposite directions by hydraulic piston-cylinder units acting ina direction of roll axes, with both piston rods being pivotallyconnected by a respective main traverse.

On each side of a connecting traverse, there is provided a pivotallysupportedly or fixedly screwed with the rolling mill stand,piston-cylinder unit for displacing an intermediate or working roll.Each piston-cylinder unit is controlled by its own servo-controlledcircuit. The displacement path of the piston-cylinder units isdetermined by displacement sensors. A malfunction of the displacementsensor, hydraulic valves, or a defective contact of a control cable cancause displacement of the piston of the displacement cylinder in anuncontrolled manner to different heights or in an opposite direction.This can lead to damage of the connecting traverse and make it unusable.

The above-described cluster mill with an axially displaceable andholding device for intermediate rolls is provided, e.g., in form of two,projecting axially outwardly arms formed as pincers (DE 24 40 495 C3).To each of the arms, a telescopically extendable piston rod of a pistoncylinder unit is connected with a connection member, with twopiston-cylinder units being arranged in the rolling mill stand housingposts on opposite sides of and adjacent to respective chocks. Suchconstructions do not have a main traverse. However, they are notprotected against an occurrence of a hydraulic or electricalmalfunction.

A similar construction (DE 35 04 415 A1) includes a bearing for a roll,which is displaceable in the chock, and a displacement carriage in whicha connection or coupling means for the journal are located. Here also,the operation of the piston-cylinder units, which extend parallel to theroll axis, can be affected, and their malfunctions can cause jamming ofthe carriage.

In another construction (EP 0 026 903), an axial displacement force ofoutwardly arranged, parallel piston-cylinder units is transmitted over amain traverse, over opposite, acting in parallel, holding plates, and apiston-cylinder unit for releasing the holding plates, when the rollunit needs to be replaced. Here, the third piston-cylinder unit takesover only the replacement function. Nevertheless, here also no measuresare provided for protection of the traverse against hydraulic orelectrical malfunctions.

Finally, known is an axially displacing and holding device fordisplaceably supported intermediate rolls of a cluster mill (DE 31 45134C2) and which produces high axial forces and which can be rapidlydisengaged from journals of the intermediate rolls for replacing therolls. Here, on each carriage, an axial support block is displaced withparallel mandrels. The coupling means is formed as a chuck forconnection with the intermediate roll journal. Here also, a traverse forthe piston-cylinder units is needed, but likewise, a danger of jammingof a carriage exists.

An object of the invention is to lock the intermediate rolls and/orworking rolls in traverses in such a way and so relocate the engagementpoint of the displacement force that the traverse cannot be damaged as aresult of a hydraulic or electric malfunction.

The set object is achieved according to the invention by providingmoving beams, which are arranged on opposite sides of the roll chock andare supported in a rolling mill stand housing post by a respectiveconnecting traverse, with the connecting traverses being pivotallyconnected to the middle of the main traverse, wherein the piston rods ofthe piston-cylinder units are pivotally connected to ends of the maintraverse, and wherein each piston-cylinder unit is controlled accordingto path by a displacement sensor.

The main advantage consists in the arrangement of the main traverse andthe connecting traverse in such a way that tensioning of the maintraverse cannot take place. A further advantage consists in a reliabledisplacement function. In addition, a simplified assembly andmaintenance can be effected. These advantages are further achievedbecause the displacement system is provided mechanically with all of thedegrees of freedom, so that a tensioning of the traverse is notpossible.

According to an embodiment of the invention, on a drive side between themoving beams, in the roll chock, a locking block for locking the roll isarranged. The advantage consists in a central arrangement, so thattransverse forces cannot be produced in case of a breakdown on anon-uniform loading of one of piston-cylinder drives.

It is further proposed to connect the chock with the locking block by atightening member.

The holding forces can be favorably applied and transmitted when theconnecting traverse is connected with the locking block by an axiallyacting tightening disc arranged in the interior of the connectingtraverse in the middle.

Advantageously, the holding force is produced by operating thetightening disc with a hydraulic tightening drive. Because of itscentral arrangement, the tightening drive is particularly simple andeasy operable.

According to further features of the invention even smallestmalfunctions can be dealt with. To this end, the length of thedisplacement path is calculated as a mean value of two displacementpaths determined by two associated with each other displacement sensors.

The piston-cylinder units are controlled in such a way that thecalculated mean value of the displacement path, which was determined bythe two displacement sensor, is communicated to respective automaticcontrol circuits of the piston-cylinder units.

The drawings show an embodiment of the invention which will be explainedin detail below. In the drawings:

FIG. 1 shows a plan view of a half of a rolling mill stand;

FIG. 2 shows a cross-sectional view along line A—A through the rollingmill stand according to FIG. 1 at the height of a tightening drive;

FIG. 3 shows a cross-sectional view along line B—B at the height of atightening member in an open position; and

FIG. 4 shows the same cross-sectional view along line B—B in a lockingposition.

According to FIG. 1, in a mill stand window of a housing post 1 of arolling mill stand 6, on opposite sides of a chock 7, there are providedmoving beams 1 a which are supported in the housing post 1 by connectingtraverses 2, respectively. The connecting traverses 2 are connected tothe middle of a main traverse 4 with a connection bolt 3 a that extendsthrough a ball-and-socket joint 3. This arrangement of the main traverse4 and of the connecting traverses 2 prevents tensioning that may becaused by a non-uniform operation of piston-cylinder units 5. The pistonrods 5 a of the piston-cylinder units 5 are pivotally attached toopposite ends 4 a, 4 b of the main traverse 4. Each piston-cylinder unit5 is controlled by a displacement sensor 10 immediately from the startof the displacement movement.

On a drive side, there is provided, between the moving beams 1 a in theroll chock 7, a locking block 8 for locking rolls 11. The locking block8 is connected with the roll chock 7 by a tightening member 9.

The holding device is so formed that the connecting traverse 2 issecured to the locking block 8 with a tightening disc 12 arranged in theinterior of the connecting traverse 2 in the middle and acting axiallyand/or radially. The tightening disc 12 is operated by a hydraulictightening drive 9 a.

The length of the displacement path 13 is calculated as a mean value oftwo displacement paths 13 determined by two, associated with each othersensors 10. The calculated mean value of the two displacement paths 13,which were determined by the two displacement sensors 10, iscommunicated to a respective automatic control circuit of thepiston-cylinder unit 5.

FIG. 2 shows a plane of the tightening drive 9 a. A turntable 14 of thetightening drive 9 a, which rotates in opposite directions, is rotatablysupported between the moving beams 1 a. The rotational movement isproduced by a hydraulically, electrically, and/or mechanically operatedlinear drive mechanism 15, so that a linear movement 16 produces arotational movement 17 in a respective direction shown with respectivearrows. In FIG. 3, the tightening disc 12, which is coaxially arrangedbeneath the tightening drive 9, is shown in an open position, with itselongate side 12 a extending vertically. Therefore, the locking block 8is axially free, and the roll 11, e.g., an intermediate roll can bepulled out axially toward the operational side in order to be replaced.

In FIG. 4, the tightening disc 12 a is displaced by the tightening drive9 a in a position in which its elongate side 12 a extends horizontally,and the locking block 8 cannot be axially displaced anymore, i.e., themoving beam 1 a, the locking block 8, the connecting traverse 2,together with the main traverse 4, form a rigid assembly.

REFERENCE NUMERALS

1. Rolling mill housing post

1 a. Moving beam

2. Connecting traverse

3. Ball-and-socket joint

3 a. Connection belt

4. Main traverse

4 a. End of a main traverse

4 b. End of a main traverse

5. Piston-Cylinder Unit for displacement

5 a. Piston rod

6. Rolling mill stand

7. Roll chock

8. Locking block

9. Tightening member

9.a Tightening drive

10. Displacement sensor

11. Roll

12. Tightening disc

12 a Elongate side

13. Displacement path

14. Turntable

15. Linear drive mechanism

16. Linear movement

17. Rotational movement

1. A cluster mill, in particular a six-high cluster mill, comprising anaxial displacing and holding device for displaceably supportedintermediate rolls and/or working rolls, wherein chocks are slidablydisplaced in rolling mill stands in a direction of a roll separatingforce, and wherein the intermediate rolls and/or working rolls, togetherwith their respective chocks, are displaceable in axial oppositedirections by hydraulic piston-cylinder units acting in a direction ofroll axes, with both piston rods being pivotally connected by arespective main traverse, characterized in that moving beams (1 a),which are arranged on opposite sides of the roll chock (7), aresupported in a rolling mill stand housing post (1) by a respectiveconnecting traverse (2), that the connecting traverses (2) are pivotallyconnected to the middle of the main traverse (4), wherein the pistonrods (5 a) of the piston-cylinder units (5) are pivotally connected toends (4 a, 4 b) of the main traverse (4), and wherein eachpiston-cylinder unit (5) is controlled according to path by adisplacement sensor (10).
 2. A cluster mill according to claim 1,characterized in that on a drive side, between the moving beams (1 a),in the roll chock (7), a locking block (8) for locking the roll (11) isarranged.
 3. A cluster mill according to claim 2, characterized in thata tightening member (9) connects the roll chock (7) with the lockingblock (8).
 4. A cluster mill according to claim 2, characterized in thatthe connecting traverse (2) is connected with the locking block (8) byan axially acting, tightening disc (12) arranged in an interior of theconnecting traverse (2) in the middle thereof.
 5. A cluster millaccording to claim 4, characterized in that the tightening disc (12) isoperated by a hydraulic tightening device (9 a).
 6. A cluster millaccording to claim 1, characterized in that a length of the displacementpath (13) is calculated as a mean value of two displacement paths (13)determined by associated displacement sensors (10).
 7. A cluster millaccording to claim 6, characterized in that the calculated mean value ofthe displacement paths (13), which was determined by the twodisplacement sensor (10), is communicated to respective automaticcontrol circuits of the piston-cylinder units (5).